Snow Observations List

From IG message 4/17/24: "Remote trigger up little bear today. Went to the groundish."

From IG: Wet slide to the ground above Quake Lake. 

We toured down the west side of the Bridger Range on the edge of Truman Gulch and found predictably weak snow on an upper-elevation NW-facing slope. Conditions were variable and transitioned to a thick crust as we moved on to a lower elevation, west-facing slope. By the time we came down the Ramp, the snow was getting wet, we saw roller balls, and we avoided steep, sun-exposed terrain. 

We dug below NW Passage. It was a 135 cm deep snowpack, dry throughout, with Fist plus hard facets and depth hoar making up the foundation (ECTP30, PST 42/100 end at 30 cm from the ground. 

We rode from the Buttermilk trailhead up Denny Creek to Lionhead Ridge, along Lionhead Ridge through Watkins Creek and to the motorized boundary at the head of Targhee Creek. 

There was a ~1" crust at the surface when we left the trailhead, with dry snow beneath. We saw our first wet loose avalanche of the day running around 11 am. By 12:30 there were dozens and many rollerballs. None of them ran particularly far or picked up too much volume.  The snow surface was moist on sunny slopes by late morning, but not more than a few inches down.

We saw one small slab avalanche that occurred since this weekend's snow. It appears to have been triggered by a snowmobile yesterday (4/1/24). It broke 10" to 2 ft deep, 50 ft wide, and ran ~50 vertical feet. It broke on a thin layer of facets beneath the new snow. Digging in the crown, dry facets at the ground were along still present and weak (fist hardness).

Signs of older avalanches were visible beneath the new snow, including one slide that broke in early March. No cracking or collapsing were observed today.

Just finished a weeklong ski from west Yellowstone to bear canyon, and thought I’d chime in that I didn’t observe anything that hasn’t been reported on already. I saw lots of deep slabs breaking near the ground, primarily on the north half of the compass. But sometimes not! There did not seem to be much activity in the newer snow, which was encouraging. In 110 miles of skiing I got a grand total of two collapses, which is close to an inverse ratio of what I experienced Nordic skiing near west Yellowstone earlier this year. It was interesting to see that despite the lack of snow, some avalanches were running almost full track. It seems like after a week of being on the snow I would see some sort of pattern, but I feel like I ended the trip with the same amount of confidence I entered it with, and didn’t feel comfortable exposing myself to hardly anything. 
 

I attached a couple photos of a slide I saw toward the head end of Swam Creek. The crown was 2-5’ deep and ~2000’ wide, and it stopped within 50’ of old growth timber. 

Toured from the buffalo horn pass trail head to the pass itself. I didn’t go super high only a little over 8600’. I was shocked by the stability the snowpack showed however. I only had 1 collapse all day and that was at the trailhead. I wasn’t getting cracking at my feet. I definitely don’t trust the snowpack but it is the least reactive place I’ve seen yet to a fresh dump. Definitely some recent wind loading up high. I’d say a foot of new snow at the pass itself and 8” at the trailhead. 

Wind was calm and there was no new snow overnight. A small whumpf in the skin track was followed by a massive one a few minutes later. I can count on one hand the number of times I got whumpfs in a skin track...rare indeed. The second one was so big it had us both deeply concerned. We peeled off the skin track after deciding to not cross a gully and soon found debris from a sizeable avalanche that released a couple days ago about 500' above us. We dug in the flank and had 100 cm of snow, 60 cm new from last week. The snowfall during the Avalanche Warning, doubled the depth and more than doubled the snow water equivalent of the snowpack. It was a large load and avalanches are breaking underneath the new snow.

Karl was using his 100 cm long Norwegian Battle Saw (pic)...a bit overkill.

Whumphing, collapsing and shooting cracks on all aspects, at all elevations. The longest shooting crack went over 100' long, shot right out in front of me on a 24deg E aspect slope. Propagating collapses out to 40 feet or so, very thin overall snowpack. Moderately nice turns on low angle slopes above 7300 but had to be very careful not to bottom out.

From my high point, it looked like the entirety of the large avalanche path on Ernie Miller Ridge E face slid recently, obvious crown on lookers L side and appeared to go wall to wall for the path (R4+). Unknown if natural.  

Very obviously terrible snowpack, it's total garbage out there. 

As we were coming out, I spotted this cracking above the creek. A sled has passed nearby on the right side ( you can see the track). The snow cracked and was starting to rub in the left (barely). 

It was above the creek and could have created a trap for someone below. 

This is just below the cabin Creek cabin where all the stands coverage. 

https://maps.app.goo.gl/KyH21E7a9vts2UAF6

Toured up bacon rind via the ridge ascent. Noted a small melt freeze crust below 7800’ with 2-3” above it. Low density snow capped a denser slab above the weak snow on the ground. signs of instability were less obvious than they have been. Still trigged several tree shaking collapses, with cracking up to 100ft above me. Riding quality was quite nice. 
noted a large avalanche that broke in the E,NE bowl off Ernest Miller, appeared to be hundreds of feet wide and several feet deep. 

ECT P 7 at 7800ft and West-Northwest facing slope. Broke approx 6-8in from the top of the snow. A LOT of woofmping pretty much everywhere we went.

30+ whumps on any slope with wind slab deeper than 5”. Happened on slopes from 0-30 degrees stayed off of and away from anything steeper. 

We experienced widespread whumpfing on all aspects between 7200'-10200'. Solid slabs were also widespread, ranging between 4''-12'', all of which were sitting on facets. We dug many handpits and the results were extremely reactive, often propagating while cutting the pit. We did not observe any natural slides. We remotely triggered a cornice and large slab, but it did not run due to the slope angle. I'm certain if we ventured into or near steep terrain, something would've run. Between 7200'-9000' we saw many wet loose on slopes > 30, and set off large roller balls on most slopes. Down low it was very warm and felt like an early spring snowpack. From 9000'-10200' it was much colder and wind slab/board was widespread on E & SE aspects. Every aspect we touched up high had shooting cracks and loud whumpfing.

Toured Ramshorn Peak from the rd. closure in Tom Miner basin. On approach we observed continuous wumpfing and shooting cracks from 7,500' to 9,900'.

A hand shear on a 20° slope with a SE aspect at 7,800' sheared cleanly upon isolation. This hand shear was completed in a rather shallow (~10") snowpack, with large facets below a slab of thicker, fist dense snow. 

Large roller balls were observed in avalanche terrain on a SE aspect at 8,300'. Alongside this observation, rather wet, sticky snow was observed throughout the tour, causing multiple glopping incidents on our skins. 

A second hand shear was preformed on a E. aspect, 20° slope around 8,400', which easily sheared clean with light hand pressure. This snowpack was notably thicker than the previous hand shear location, measured closer to 30" with facets below a 6" slab of fist-dense snow. 

Near our second hand shear, a 2' cornice on at 27° slope created a large shooting crack that propagated across the whole slope (contained by trees). If said cornice and slab was on a steeper slope, we are pretty sure this slab would've slid. 

A several day old avalanche was also spotted on the windward portion of Ramshorn's SW shoulder around 9,800'. Upon further inspection, this slide seemed to be natural and had a crown of ~1.5' with a width of approximately 300'.

Clear evidence of recent wind events (e,g. Thursday's 75mph gusts) were clear on the SE face of Ramshorn, creating several inch thick wind slabs on the face and removing the majority of the snow above from the SW ridge and peak above 10,000'. 

From FB: Taylor’s Fork today, 8-10 inches of new snow last night. A few small slides but tons of cracking.

A small avalanche was noted in Black Bear Canyon on a northeast facing slope. Snow was wind loaded, cornices were seen on nearby slopes. This appeared to be storm slab and likely rider triggered. Slope was greater than 30 degrees. 

I skied up toward fawn pass today, and had a few notable observations. We had multiple collapses during our ski, and one 40’x40’ slope had a large collapse on the trip up and again on the way down. I noticed one meadow that had collapsed before we were out, and the new snow had sheared off of several downed logs. Most notably, my tracks from a month ago were easy to follow in a few places. 

We toured into Bacon Rind which involved navigating downfall at the start which became easier as the snow got deeper. We found 2 feet of snow on the ground, all of it sugary facets capped with big feathers of surface hoar. We had no whumpfing or cracking and saw no avalanches. We dug 2 snowpits and got no breaks in our stability test because the weak, sugary snow did not have a denser slab sitting above it (ECTX). The danger is LOW, yet new snow, even a small amount, may ramp the danger up. For now, it is weak and stable. The skiing progressively got worse as we descended, which was no surprise. 

Massive surface hoar on sheltered slopes outside of West Yellowstone 

Dug into the hillside right before going up the creek. Snow pack was 75 cm deep consisting of three layers. Bottom 35cm is obviously faceted, grain size is around 2mm. Very thin ice crust at around 35cm. Upper 35 cm of snow is brand new snow from this current storm, precipitation particles, low density, with minor wind effect. Performed a quick Compression Test and the ice crust layer failed on the second tap. Sudden collapse, clean sheer. Snowmobiled a small test slope next to pit and got no shooting cracks or whoompfs.